WCDMA technology provides well established techniques for spectral utilization in high load mobile communication systems. Interference Cancellation (IC) and Interference Suppression (IS) may be used in WCDMA systems in order to achieve better performance in terms of e.g. peak data rates, coverage, system throughput and system capacity. IC and IS are applicable both for DownLink (DL) and UpLink (UL). However, most load limiting parameters that are difficult to control are connected with the UL signaling.
The basic idea behind IS is to combine the received radio signals such that interference is suppressed and the Signal-to-Interference-and-Noise Ratio (SINR) is maximized. There are many ways to achieve IS according to prior art. Non-exclusive examples are interference rejection combining, where the signals from more than one antenna are combined in order to suppress interference, and Generalized Rake+ (GRake+) (also referred to as non-parametric GRake), where interference is suppressed by whitening of the interference both in the temporal and the spatial domain.
Even though there exist several already known ways to achieve IS at link level, the knowledge of how to utilize the link level gain in order to increase the capacity or cell throughput in a WCDMA network is limited.
It first needs to be stressed that when advanced receivers such as GRake+ are applied, the conventional load measure without interference suppression is no longer valid. The conventional load measure is namely based on the fact that each user affects all other users in exactly the same way, from a load perspective, since conventional receivers do not handle the interference from other users in any explicit way in the receiver. However, with advanced receivers such as GRake+, a user's effect on other users is not the same on all users, and the effect is a function of the IC or IS efficiency.
Further, the load of the cell is used for scheduling e.g. of Enhanced UL (EUL) users, new and old. When doing this, the cell load measure described for GRake+ provides a larger total scheduling headroom as compared to pre-determined thresholds. However, the problem with the solutions in prior art is that there is no technology in prior art that allows the scheduler to address the detailed impact and contribution of different existing users, to the uplink Rise-over-Thermal (RoT) after GRake+ processing, in the scheduling process.